The 4th Harmony is combine Qi and Shen
qi he yu shen 气合于神
Now you have a powerful form! Yet there is more. Some martial artists stop here, their Qi abundant and their lives full of energy. There is another level. You must reignite that fire in your belly and change the energy into shen. The spirit must follow the qi to the upper dan tian and build there. You must allow your spirit to then touch every fiber of your being, every hair on your body.
Through this your awareness will become truly keen, you will experience things on a new level. A spiritual power is a strong thing if developed. Have you ever seen a truly intimidating person just stare another down, see a person cower in fear, knowing they are powerless against them — this is a very similar concept, it’s a subconscious event that one cannot explain. If developed your shen can be a handy tool for health and combat.
This level is just the 4th but still few reach this level. They do not make their Qi abundant and thus cannot mix and convert it into Shen. They will pontificate on the finer point of hormones and vitality, describing Shen in terms that they can relate to. Is it this, yes– but it is so much more. Your spirit can expand beyond the physical limits of these things, expand upon your own body. It is an awareness and vitality only few know. How can you tell if a person has started down this path? They will become calm and relaxed, their outward appearance will radiate their inward strength and vitality. A person will start to develop yansheng (spirit from the eyes 眼神). It’s a difficult level to perceive let alone master, but the journey towards this harmony will make one healthy, strong, and vibrant.